Is benztropine (an anticholinergic medication) effective for treating hyperhidrosis (excessive sweating)?

Benztropine for Hyperhidrosis

Benztropine is not recommended as a treatment for hyperhidrosis due to its potential for serious adverse effects and the availability of safer, more effective alternatives.

Mechanism and Concerns

• Benztropine contains structural features of atropine and can produce anhidrosis (inability to sweat), which makes it inappropriate as a treatment for excessive sweating 1
• The FDA label specifically warns that benztropine should be administered with caution during hot weather due to its anticholinergic properties that can impair sweating 1
• Severe anhidrosis and fatal hyperthermia have occurred with benztropine use, particularly when given with other anticholinergic medications 1

Preferred First-Line Treatments for Hyperhidrosis

Topical Treatments

• Topical aluminum chloride solution is the initial treatment of choice for most cases of primary focal hyperhidrosis 2
• For craniofacial hyperhidrosis specifically, topical glycopyrrolate (0.5% solution) is considered first-line treatment with significant reduction in sweating and minimal side effects 2, 3

Second-Line Options

• Botulinum toxin injection (onabotulinumtoxinA) is considered first- or second-line treatment for axillary, palmar, plantar, or craniofacial hyperhidrosis 2, 4
• Iontophoresis should be considered for treating hyperhidrosis of the palms and soles 2

Oral Anticholinergic Options (When Topical Treatments Fail)

• Oral anticholinergics should only be used as adjuncts in severe cases when other treatments fail 2
• Preferred oral anticholinergics with evidence for hyperhidrosis include:
  • Glycopyrrolate - reported improvement in symptoms with adverse events in 38.6% of patients 5
  • Oxybutynin - improved symptoms in an average of 76.2% of patients but caused dry mouth in 73.4% of patients taking 10 mg/day 5
  • Methantheline bromide - associated with 41% reduction in axillary sweating 5

Safety Considerations

• Oral anticholinergics for hyperhidrosis are associated with significant adverse events, with dry mouth being the most common side effect 5
• Approximately 10.9% of patients discontinue oral anticholinergic therapy due to adverse events, primarily dry mouth 5
• Benztropine specifically carries warnings about impaired mental and physical abilities, paralytic ileus, hyperthermia, and heat stroke, especially when combined with phenothiazines or tricyclic antidepressants 1

Treatment Algorithm

1. Begin with topical treatments:

   • Aluminum chloride for axillary, palmar, or plantar hyperhidrosis 2
   • Topical glycopyrrolate for craniofacial hyperhidrosis 3

2. If topical treatments fail, consider:

   • Botulinum toxin injections 2, 4
   • Iontophoresis (for palms and soles) 2

3. For refractory cases, consider oral anticholinergics:

   • Glycopyrrolate, oxybutynin, or methantheline bromide 5
   • NOT benztropine due to safety concerns 1

4. For severe cases unresponsive to above treatments:

   • Consider local surgery or endoscopic thoracic sympathectomy 2

Given the FDA warnings about anhidrosis and hyperthermia with benztropine, along with the availability of safer and more effective treatments, benztropine should not be used for hyperhidrosis management.